Haeusler. — Notes on some Foraminifera. 19? 



and in many tertiary and even older formations of Europe. The 

 specimens are, as a rule, of good size, and even the most delicate 

 tests remarkably well preserved. They can easily be picked out 

 with an ordinary pocket-lens, and examined with a 1-inch 

 objective. 



In the porcellaneous group, the genus Miliolina is best repre- 

 sented, while the allied genera, Nubecularia, Biloculina, and 

 Spiroloculina occur only in isolated individuals. Eibbed and 

 otherwise ornamented species are exceedingly rare. The Milio- 

 lines are very variable, and run so gradually into each other 

 that no distinct lines of demarcation can be drawn. Monstrous 

 specimens are frequent, and difficult to determine. 



The second large group is almost entirely absent. It is evi- 

 dently in deeper water that we must look for arenaceous forms 

 of the families Astrorhizidai, LituoUdcc and TextularidcB. The most 

 interestiug species from these shores is Thurammina papillata, of 

 which one of the slides contains two small spherical specimens. 



The LagenidcB, belonging to the third group {Hyalinea), are 

 also exceedingly rare. The most beautiful, delicately orna- 

 mented, Lagena squamosa is the most abundant. The higher 

 rotaline forms are well represented, and belong to geographi- 

 cally widely diffused types. 



1. Gen. Nubecularia. 



No good specimen, but small fragments of a variety of N. 

 lucifuga, Defr. 



2. Gen. Biloculina. 



Eare specimens of B. ringem, Lam. 



3. Gen. Miliolina. 



With the typical forms, numerous abnormally developed 

 shells were obtained, which can be considered as intermediate 

 forms between the quinqualoculine and triloculiue MiliolmcB and 

 the symmetrical BiloculincB and SpiroloculincB, and the different 

 dimorphous groups. 



It is an easy task to construct long series which show 

 almost every conceivable deviation with regard to general form, 

 arrangement and relative size of chambers, shape and position 

 of the aperture, and colour, which prove clearly how little value 

 we have to attribute to morphological characters, which are 

 often considered of greatest importance for the systematical 

 arrangement of species, and even whole genera. Some speci- 

 mens are almost symmetrical, others show different modes of 

 growth at different ages. Frequently the final chamber does 

 not follow the general plan of growth. A careful comparison 

 of numerous specimens is necessary to ascertain the relationship 

 betWBBn the widely different modifications of the simplest types. 



